A "End Chat" button for the customer to end the chat session with Sinch Contact Pro live agent

Customer can have the flexibility to end the chat session with live agent. Currently only the agent can end the chat. 

Scenarios:

1. All the agents are busy, customer is waiting in the chat queue. Customer can have the option to end the chat so the queue can stop sending the in queue message to the customer.

2. Customer decided to end the chat with live agent and return to the bot.